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10 * 172.16 * 192.168 ... why?

 
 
antonio
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      04-13-2008, 01:18 PM
hi
does have any sense this numbers?

10, may be, it's easy to remember for our decimal-sistem
192 it's the first of the C class... but why *168*?
and 172.16?

it seems random...
 
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Unruh
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      04-13-2008, 02:51 PM
antonio <(E-Mail Removed)> writes:

>hi
>does have any sense this numbers?


>10, may be, it's easy to remember for our decimal-sistem
>192 it's the first of the C class... but why *168*?
>and 172.16?


It's random. So what?


>it seems random...

 
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Dave Uhring
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      04-13-2008, 03:17 PM
On Sun, 13 Apr 2008 15:18:46 +0200, antonio wrote:

> does have any sense this numbers?
>
> 10, may be, it's easy to remember for our decimal-sistem 192 it's the
> first of the C class... but why *168*? and 172.16?


Because those network blocks had not already been assigned by ICANN when
they reserved them?

> it seems random...


Only to random minds : >
 
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Moe Trin
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      04-13-2008, 04:45 PM
On Sun, 13 Apr 2008, in the Usenet newsgroup comp.os.linux.networking, in
article <4802096d$0$29603$(E-Mail Removed)>, antonio wrote:

>does have any sense this numbers?


It was what was available.

>10, may be, it's easy to remember for our decimal-sistem


/8 (formerly called Class A) address ranges are limited. There were
only 128 in the original scheme, and they threw away two of those
(0.0.0.0/8 and 127.0.0.0/8) leaving 126. Today, 96 of them have been
assigned. See http://www.iana.org/assignments/ipv4-address-space. In
fact, 10.0.0.0/8 was the old DARPA address range and it was retired.
See RFC1627 for indications of the problems about the re-use of that
address range.

>192 it's the first of the C class... but why *168*?
>and 172.16?
>
>it seems random...


It's what was available. See RFC3330 for further hints. Address space
is in demand, which is why IPv6 was developed. As of last month, there
were 2609197794 IPv4 addresses in use - 70.4 percent of the available.
For perspective, the same figures for last December (3 months earlier),
were 2564407724 and 69.2 percent. At the end of 1993, about the time of
RFC1597 (which was replaced by RFC1918), the figures were 1233944064 and
33.3 percent, so one third of the address space was already in use.

Old guy
 
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antonio
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      04-13-2008, 05:06 PM
> It's random. So what?

it's random?
well! why?


(or is it a radom reason too?)
 
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antonio
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      04-13-2008, 05:06 PM
> Because those network blocks had not already been assigned by ICANN when
> they reserved them?


this is the best (and maybe the only...) hypothesis...
 
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antonio
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      04-13-2008, 05:10 PM
Moe Trin ha scritto:
> On Sun, 13 Apr 2008, in the Usenet newsgroup comp.os.linux.networking, in
> article <4802096d$0$29603$(E-Mail Removed)>, antonio wrote:
>
>> does have any sense this numbers?

>
> It was what was available.
>
>> 10, may be, it's easy to remember for our decimal-sistem

>
> /8 (formerly called Class A) address ranges are limited. There were
> only 128 in the original scheme, and they threw away two of those
> (0.0.0.0/8 and 127.0.0.0/8) leaving 126. Today, 96 of them have been
> assigned. See http://www.iana.org/assignments/ipv4-address-space. In
> fact, 10.0.0.0/8 was the old DARPA address range and it was retired.
> See RFC1627 for indications of the problems about the re-use of that
> address range.
>
>> 192 it's the first of the C class... but why *168*?
>> and 172.16?
>>
>> it seems random...

>
> It's what was available. See RFC3330 for further hints. Address space
> is in demand, which is why IPv6 was developed. As of last month, there
> were 2609197794 IPv4 addresses in use - 70.4 percent of the available.
> For perspective, the same figures for last December (3 months earlier),
> were 2564407724 and 69.2 percent. At the end of 1993, about the time of
> RFC1597 (which was replaced by RFC1918), the figures were 1233944064 and
> 33.3 percent, so one third of the address space was already in use.
>
> Old guy



WOW!
amazing!

 
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antonio
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      04-13-2008, 06:26 PM
> It's what was available. See RFC3330 for further hints. Address space
> is in demand...


....and maybe the most *sorted* adresses was demanded first...

 
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ray
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      04-14-2008, 12:41 AM
On Sun, 13 Apr 2008 15:18:46 +0200, antonio wrote:

> hi
> does have any sense this numbers?
>
> 10, may be, it's easy to remember for our decimal-sistem 192 it's the
> first of the C class... but why *168*? and 172.16?
>
> it seems random...


By my calculations, 10 * 172.16 * 192.168 = 330836.42880.
 
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Moe Trin
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      04-14-2008, 08:11 PM
On Sun, 13 Apr 2008, in the Usenet newsgroup comp.os.linux.networking, in
article <48025192$0$29596$(E-Mail Removed)>, antonio wrote:

>> It's what was available. See RFC3330 for further hints. Address space
>> is in demand...

>
>...and maybe the most *sorted* adresses was demanded first...


That is more difficult to say. A quick grep of the delegation files from
the five RIRs looking for IPv4 addresses in the 192.x.x.x range that were
allocated/assigned before the end of 1993 turns up 12166 lines. These
allocations/assignments are coming from three RIRs (APNIC, ARIN, and RIPE
because AFRINIC and LACNIC didn't exist until later), and it appears that
they were allocating space individually. Each person doing these
allocations/assignments was following their own procedure within those
blocks - such that one may have started at the beginning of his block
and assigned consecutive ranges, while another may have been trying to
assign blocks based on the region or country. (Recall that originally,
ARIN was making all allocations/assignments, then RIPENCC took over for
Europe and Africa, then APNIC took over the Asia/Pacific part of the
world, eventually followed by LACNIC for Central/South America and
most recently, AFRINIC for Africa.) This more or less is the same
"problem" about how do you assign IP addresses on your LAN. Do you
start at x.y.z.1 and work up? Or have you some numbering scheme, where
hosts x.y.z.1 through x.y.z.9 are routers and DNS servers, hosts x.y.z.10
through x.y.z.N are workstations located on the first floor or this building
or some similar idea?

Old guy
 
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